The present invention relates in general to devices used in the field of dentistry, and more particularly, to a dental matrix strip.
A dental matrix is typically used by dentists to retain packed filling material in position within a tooth prepared cavity. Such devices have been in use for a considerable time.
Prior art examples of various dental matrix, shim and clamping devices are shown in U.S. Pat. Nos. 5,620,322 (Lococo), 3,795,052 (Mowery), 5,788,587 (Meyer), 6,007,334 (Suhonen), 6,234,793 (Brattesani et al.), 5,730,592 (Meyer), 677,268 (Power), 532,723 (Dennis), 164,870 (Palmer), 1,669,231 (Curran), 5,425,635 (Croll), 5,342,194 (Feldman), 6,293,796 (Trom et al.), and 6,325,625 (Meyer). Various matrix devices fashioned from thin sheet-like material are shown in these patents. Several of the devices are intended for use with bicuspid and molar teeth.
One of the difficulties encountered by dentists when filling an interproximal cavity (a cavity that develops on the side of a tooth) is in securing the filling material within the cavity during the curing time for the filling material. Typically, a dental matrix device is used to retain filling material within the cavity while the filling material hardens or is cured. If the matrix is not securely stabilized, the matrix can be inadvertently moved by the patient or dentist during the procedure. Any movement of the matrix from its interproximal position is likely to allow the filling material to flow outside the cavity preparation, or create a void in the filling material.
Typical matrix bands of the prior art used by dentists are thin elongated plastic strips (oftentimes made from Mylar(copyright) or polyester film) having a thickness ranging from less than 0.001xe2x80x3 to 0.030xe2x80x3. The known prior art dental matrix devices have failed to provide a reliable mechanism for securing the matrix in an interproximal position, without the separate use of wedge devices. Due to the variations in the interproximal anatomy, conventional wedge devices often will not fit between the teeth properly.
What is needed is a dental matrix device that includes a design for readily inserting the device in an interproximal position and a mechanism for securing the device in position between adjacent teeth to retain filling material within a cavity during the curing process and to prevent inadvertent movement of the matrix. A dental matrix that includes such a position securing mechanism and that accommodates a wide range of interproximal spacing is needed.
A dental matrix strip, according to one aspect of the present invention, comprises an elongated flexible strip having a front surface, a rear surface, an upper edge, a lower edge, a first end and a second end, and the strip includes an elongated tapered portion disposed on the front surface of the strip and extending outward from the front surface of the strip, the tapered portion situated near and along the upper edge of the strip and having a larger height above the strip substantially near the center of the strip and diminishing to nominal thickness near the first end of the strip.
One object of the present invention is to provide an improved dental matrix device.
Another object of the present invention is to provide a dental matrix having an anchoring feature to secure the matrix in position between teeth, without the need for a separate wedge device.
Yet another object of the present invention is to provide an inexpensive dental matrix device.
Still another object is to provide a dental matrix that is universally applicable to any of a variety of inter-dental tooth spacing, and anatomy.
These and other objects of the present invention will become more apparent from the following figures and description of the preferred embodiment.